I like the wikipedia list of musical symbols: https://en.wikipedia.org/wiki/List_of_musical_symbols More on reddit.com

I used to remember it like this: middle C, bass F and treble G are simple top most line on the staff is F (call it flag F) the last line on the staff is G (call it ground G) remember that an octave will always have a line and space, meaning if middle C is on a line, then the C above and below will sit on a space. All that was a long time ago, most of these things I saw on Hoffman Academy. Now I don't need to think about any of that. More on reddit.com

Handy way to avoid learning stuff... ;-) It reminds me of when I was teaching guitar to young kids (aged 8-10) and most of them would find it easier to play from notation by writing the note names in, much like this. I didn't stop them doing it - I realised it was a crutch, but at least it helped them play, and they did wean themselves off it in the end. I.e, they learned the notes, and where the notes were on the instrument, but - for a while - still needed that extra link to cement the "notation > fingers" connection. IOW, I can see a use for this, but it seems like just one more app to avoid an aspect of experience. It suggests that anyone who finds this excitingly useful would ultimately want an app that played the music for them so they could just sit back and listen! I mean, playing music is hard, right? Who would put themselves through that if they didn't have to? ;-) Get someone else to do it, or get an app to do it.... More on reddit.com

Going to give you the old school advice for getting to sight reading. First off, no YouTube. Second, no memorizing. Third, only see hands in peripheral vision. Fourth, get a graded beginners book and go through those lessons. Once you have finished that book, go on to the same course”s book 2. By then you pick up a book of easy piano popular or classical music that is BELOW your current study level. You randomly pick out one piece from that at each practice session and sight read it at as slow a tempo as you need. Keep with the graded course as well. More on reddit.com